17-valerate ester of 6{60 ,9{60 -difluorohydrocortisone, its compositions and use as an anti-inflammatory agent

ABSTRACT

There has been prepared the new 6 Alpha ,9 Alpha difluorohydrocortisone 17-valerate useful as an anti-inflammatory agent. This compound may be incorporated in a topically suitable pharmaceutical carrier to obtain pharmaceutical compositions which may be administered locally as ointments, creams or lotions for the treatment of inflammatory conditions.

Field of Search ..lMachine Searched Steroids States [151 3,694,471 Ercoli et al. [451 Sept. 26, 1972 s41 l7-VALERATE ESTER or 601,901- [56] References Cited DIFLUOROHYDROCORTISONE, ITS COMPOSITIONS AND USE AS AN UNITED STATES PATENTS ANTI-INFLAMMATORY AGENT 2,838,499 6/1958 Spero et al ..260/239.55 72 Inventors: Alberto Erco, Milan; Rinaldo Gab 3,152,154 10/1964 EICOll 6 31. ..260/397.45 di Cal-ate Brianza both of Italy 3,297,729 1/1967 Mancini et al ..260/397.4 3,312,590 4/1967 Elks et al. ..167/58 [731 Asslgnee= Warner-Lamb? Pharmaceutical 3,383,394 5/1968 Weber et a1. ..260/397.45

Company, Morris Plains, NJ.

[22] Filed: June 8, 1970 Primary Examiner-Henry A. French Attorney-Albert H. Graddis, Henry E. Millson, Jr., 1 1 4*? 3 Frank s. Chow, Neil D. Edwards and Anne M. Kelly Related u.s. Application Data ABSTRACT [63] Continuation-impart of Ser. No. 707,934, Feb. There has been p p the new 601,90!- 26, 19 3, b d difluorohydrocortisone l7-valerate useful as an antiinflammatory agent. This compound may be incorporated in a topically suitable pharmaceutical carrier [52] US. Cl ..260/397.45, 424/243 to obtain pharmaceutical compositions which may be [51] lnteCl ..C07c 169/34 administered locally as ointments, creams or lotions for the treatment of inflammatory conditions.

1 Claim, No Drawings l7-VALERATE ESTER OF 60:,901- DIFLUORQHYDROQORTISONE, HTS COMPUSITHONS AND USE AS AN ANTH- ENFLAMMATORY AGENT ment of inflammatory conditions and diseases.

The new steroid compound of this invention is the l7-valerate of 601,9aadifluorohydrocortisone or 601,901- difluoro-l 1B, 1 7a,2 l -trihydroxy-pregn-4-en-3 ,20-dione l7-valerate, represented by the following structural female t,

This compound shows anti-inflammatory properties particularly high in comparison with those of the known 6a,9a-difluorohydrocortisone or its 2l-esters. it is also unexpectedly more active than the previously known 17-esters of potent corticosteroids having the prednisolone structure. Prednisolone is recognized to be more potent than hydrocortisone and it is known that the introduction of a 16-niethyl substituent in combination with a 9a-fluoro group produces a further increase in the anti-inflammatory activity of the parent compound. The new steroid l7-ester of this invention which is unsubstituted at the l6-position and which lacks the characteristic A -diene structure exhibits an anti-inflammatory activity several times greater than that of l7'ester analogs of 'l-methyl'substituted 9afluoroprednisolone.

On account of its particular properties, the compound of the present invention is useful for the treatment of inflammatory conditions and diseases, particularly when administered by topical application.

The compositions of this invention contain the active steroid in intimate admixture with a suitable carrier or excipient and may be in solid, semisolid, liquid or viscous form. The active ingredient may be com pounded, for example, with the usual carriers for tablets, pellets, suppositories, powders, ointments, lotions, creams, emulsions, aqueous suspensions and other forms particularly suitable for topical use. The carriers employed are those which have alreadybeen proposed for use in manufacturing preparations for topical use, such as for example fats of animal origin and vegetable oils, saturated or unsaturated fatty acids, aluminum stearate, alcohols, polyalcohols, such as for example glycerol, propylene or polyethylene glycols, waxes, aliphatic hydrocarbons or lanolin, together with comparatively high quantities of water. Other carriers which can be used are hydrophilic bases, cholesterol, vaseline, vaseline oil, silicones which are physiologically inert, sodium alginate and in addition stabilizing, thickening and coloring agents and perfumes. The compositions of the present invention can also contain preservative or bacteriostatic agents such as for example esters of p-hydroxy benzoic acid, i.e. methyl-, ethylor propyl-p-hydroxy benzoate, mercuric derivatives such as for example the merthiolate, or quaternary ammonium derivatives such as for example cetyltrimethyl-ammonium bromide, which besides the surface active action possess a good bacteriostatic activity.

Other active ingredients compatible with the new steroid of this invention, such as for example antibiotics, local anesthetics or sulphonamides can also be incorporated in the topical anti-inflammatory compositions if these added properties or characteristics are desired.

The l7-valerate ester of 6a,9a-difluorohydrocortisone is included in the compositions of this invention in an amount sufficient to produce the desired therapeutic effect upon the inflammatory process or condition. Advantageously the compositions will contain the active ingredient in an amount of from 0.0005 to 5 percent and preferably from 0.005 to 0.5 percent by weight.

The compositions of this invention are indicated for the treatment of dermatitides of various type, psoriasis and allergic conditions which respond to the topical application of anti-inflammatory steroids.

The l7-valerate of 6a,9a-difluorohydrocortisone is prepared by treatment of the corresponding diol with a lower alkyl orthovalerate in the presence of an acid catalyst followed by acid hydrolysis of the resulting l7a,2l-orthovalerate according to the following scheme;

CHzOH III wherein R represents a lower alkyl, preferably methyl.

The orthoesterification step is carried out at a temperature ranging from 60 to l30C and preferably around l()()-l lC for a period of 824 hours,

distilled water, 5 parts diethyl ether and l0 parts 4 percent croton oil in diethyl ether (v/v). Control rats were treated with the above vehicle, topically applied to both sides of the right external ear via curved, felt whereby the l7a,2l-orthovalerute of Formula lll forms 5 "W lf i until h surfaces PP as a mixture f two i i orthoemers, h uniformly moist. Test animals were treated with the orthovalerate thus obtained is then hydrolysed with a salne Y m whlch :hfferem amcfums of two mineral or organic acid to give the l7-monovalerate l. folds under exammatfofl were dlssolved- SIX hours In order further to illustrate this invention, the follater: when the PlllOglstlc "i p to (flown was lowing examples are given l0v maximal, each animal was lightly etherized and both ears were removed and individually weighed on a tor- EXAMPLE 1 sion balance. The antiphlogistic effect of the test steroid was expressed by the decrease in weight of the A mlxmre of 1 g y 3 right ear. Forty-eight hours after topical application of cc of methyl orthovalerate and 10 mg of p f f the materials, the animals were sacrificed and the thymi sulfomc 5 cc f d1methylfrmam1de 15 were removed and weighed on a torsion balance. The tamed overnight under nitrogen stream at 105C (bath weight f the thymus was taken as an i d f h temperature). Then there are added a few drops of Systemic ff t f the compouh Pyndme and solvent 15 FvaPorated under vacuum The results obtained in two replicate tests are re- The resldue 15 take up with fiflh mi tfiltqfi ported in Table I below.

TABLE I Sterlod Right ear weight Thymus weight cone (mg) mgJml Compound vehicle 1 assay 2 assay 1 assay 2 assay Control 134.0=l.- 5.5 127. 2=!=3.63 136.8519 220. 5:l=10.9 0. 05 121. 2311.5 125.7e.4e 121.s=+=4.a 197. :1.4 Betamethasone17-valerate 0.25 127.1=l;4.7 l22.3=l=5.00 136. 2112.3 152.7=l=0.9 1.25 1l8.3=l=6.1 110914.79 04.15am 111.5;l:3.7 0.05 91.2%.; 109.2i2.96 129.5:h9.6 208.7=l;12.4 6a. Qa-dllluorohydrocortlsone17-valerate....{ 0.25 90.3:b5.0 90. 93:3.46 129.6;b14.5 202. 9=|=8.3 1.25 s2.6=l=2.a 86.513.19 75.8:l:8.1 131.0=l;6.0

* Average :1: standard error.

and the product crystallized from a methanolmethylene chloride mixture. The l7a,2l-(1'-methoxy)-n-pentylidenedioxy-6a,9a-difluoro-A -pregnenl1B-'ol-3,20-dione is so obtained; M.P. l79-l83C, [a]D=+70.5 (dioxane, c=0.5 percent). U

A suspension ofl g of this product in l0 cc of methanol is treated with 0.5 cc of an aqueous solution of oxalic acid and heated on water-bath at -50C. When the product is completely passed into solution, the mixture is concentrated under vacuum. The residue is then shaken with water, the insoluble product is filtered off and then dried. The 6a,9a-difluorohydrocortisone l7-valerate is thus obtained which, when crystallized from acetone-ether, melts at l86-l90C, a 1 31 i 2 (dioxane, c 0.5 percent). Yield: 75 percent.

EXAMPLE 2 Anti-inflammatory activity The l7a-valerate of 6a,Qa-difluorohydrocortisone was evaluated for its local antiphlogistic effect and for its systemic action in comparison with betamethasone l7-valerate, the compound which is recognized as one of the most topically active anti-inflammatory agents with a low systemic effect.

For this evaluation, the recently developed ear irritant test of Tonelli, L. Thibault and I. Ringler (Endocrinology, 77, 625, 1965) was used in order to determine not only the anti-inflammatory potency but also the degree of absorption of the steroid through its effect on thymus weight. The test was performed on Wistar or Sprague-Dawley rats of both sexes weighing about 60 g. The right ears of the rats were treated with a phlogistic agent consisting of 4 parts pyridine, 1 part These results show that the l7-valerate of 611,901- difluorohydrocortisone exhibits a local antiphlogistic activity at least 25 times greater than betamethasone l7-valerate (the low dose of the former being more effective than the high dose of the latter), while the systemic thymolytic efiects of the two compounds are practically equivalent.

EXAMPLE 3 An ointment having the following composition is prepared for external use following accepted pharmaceutical compounding procedures:

Components Percent By Weight 6a,9a-difluorohydrocortisone l7-valerate 0.05 Cetyl alcohol 0.50 Anhydrous lanolin 5.00 Distilled water 5.00 Benzyl alcohol 0.50 Liquid paraffin 20.00 White soft paraffin 68.95

Melt the cetyl and benzyl alcohols, the liquid paraffin and the white soft paraffin at C, add the active ingredient, then the lanolin previously mixed with the water. Refine twice.

Methylparaben 0.025 Cetyl trimethylammonium bromide 1.000 Propylene glycol 12.000 Stearyl alcohol .000 White soft paraffin 12.775 Liquid parafiin 22.500 Distilled water 36.660

Melt the stearyl alcohol, the white soft paraffin and the liquid paraffin at 75C, add a solution of the active ingredient in the propylene glycol, then the other in- 10 gredients previously mixed with the water and warmed to 75C. Refine twice. EXAMPLE 5 Ointment having the following composition:

Components Percent By Weight 6a,Qa-difluorohydrocortisone 17-valerate 0.20 Lanolin 14.45 Liquid paraffin 17.75 Neomycin sulphate 0.40 White soft paraffin 67.20

Add the 6a,9a-difluorohydrocortisone l7-valerate and the neomycin sulphate to the other ingredients previously melted at 75C and refine twice.

in place or besides the neomycin sulphate other topically active antibiotics can be used, such as colistin sulphate, bacitracin, gramicidin, chloramphenicol or the sulphonamides.

EXAMPLE6 Lotion having the following composition:

Components Percent By Weight 6a.9a-difluorohydrocortisone l7-valerate 0.4 Ethyl alcohol 40.0 Water 59.0 Cologne water 0.6

The active product is added to a clear mixture of the Dissolve the active product in the alcohol and add to a clear mixture of the other ingredients.

We claim:

1. 6a,9a-Difluorohydroconisone l7-valerate. 

